1. Field of the Ivention
The present invention relates to an improved, simple, energy-conservative, yet efficient method and apparatus for the extraction of sulfur dioxide and water vapor from gaseous effluent emitted upon combustion of sulfur-bearing materials.
Recent widespread attention has been directed toward the environmental impact attendant the combustion of sulfur-bearing fuels as the source of essentially sulfur-free fuels becomes exceedingly scarce. As these sulfur-bearing fuels are combusted in, for example, the production of electrical power, copious quantities of sulfur dioxide, partially associated with water vapor, are generated and must be removed from the gaseous effluent before discharge thereof to the atmosphere. The present invention is directed to both achieving these ends and, additionally, providing for the easy recovery of sulfur dioxide in commercially usable form. Moreover, the present invention is directed to achieving these ends while minimizing substantially the energy requirements therefor.
2. Description of the Prior Art
Many techniques have been developed to remove noxious sulfur dioxide from stack gases emitted upon combustion of sulfurous fuels. Chemical scrubbers and catalytic, fluidized beds have been advanced for these purposes; however, most often these are complex apparatus of high cost which, while removing the sulfur dioxide component, generally do not yield an easily recoverable end product, should such be desirable.
Similarly, other systems employ extractive techniques for the removal of sulfur dioxide from the gaseous effluent which yield sulfur dioxide trapped in a catalytic or absorbent agent. Thus, not only is recovery of the sulfur dioxide made more difficult but, additionally, the catalyst or sorbent must then be regenerated after a relatively short amount of time to render same continuously useful.
Other systems rest upon the ease of liquefaction of sulfur dioxide from its gaseous state for their efficacy. See, for example, Hasche, U.S. Pat. Nos. 1,810,312 and 1,939,694. However, such systems too present considerable drawbacks. For instance, and quite importantly, furnace efficiency may be reduced as the result of surging through the system.
Accordingly, the need exists to efficiently, yet simply, extract sulfur dioxide and associated water vapor from gaseous effluent emitted from the combustion of sulfur-bearing materials and allow recovery of sulfur dioxide component in a commercially usable form. The need also exists to realize these objectives while minimizing the energy requirements therefor.